Polymer-coated paper-based products have numerous applications, more particularly in paper varieties whose ink jet printability can be improved by the polymeric coating, i.e., all graphic papers, natural papers, paperboard and cardboard. In all these applications, the surface of the paper-based construction material is altered, as is indeed desired for the abovementioned applications such as printability or barrier properties. Paper-based products coated with biodegradable polymer (blends) are known from WO2010/034712.
However, there are numerous applications where the surface properties of the paper are actually desired. In corrugated fiberboard production, the untreated surface of paper has distinct advantages. When the corrugated plies are produced on the so-called fluted rows, the untreated surfaces of paper do not adhere. On the other hand, untreated papery materials of construction have insufficient wet strength or oil resistance for numerous applications. Subsequent impregnation or waxing of the papers leads to issues in the recycling of the papery materials of construction.
German Laid-Open Specification DOS 2124092 describes wet-strength corrugated fiberboards having a corrugation with a paper/polyethylene/paper construction. This embodiment is disadvantageous in that the paper/polyethylene assembly is not simple to recycle using customary methods (e.g., deinking in the case of newspaper by the method described in EO 09174077.9).